Neural network providing integrative perception of features and subsecond temporal parameters of sensory stimuli

Abstract

Neural network providing simultaneous perception of features and temporal parameters of sensory stimuli is presented. It is postulated that temporal parameters "when" are processed together with feature parameters "what", and associations "what-when" are encoded in neocortical areas wherein parameters "what" are perceived. Rate of "internal clock" is inversely proportional to the time of repeated excitation of cortical area via the subthalamic, pedunculopontine and thalamic nuclei. This time depends on dopamine-modulated functioning of parallel cortico-basal ganglia-thalamocortical loop that promote disinhibition of mentioned nuclei and contrasted amplification of firing of cortical neurons initially activated by a stimulus. Parameter "when" is proportional to the number and duration of cycles of repeated cortical excitation. Time counting starts involuntary by a stimulus, or voluntary due to prefrontal cortex activation. Proposed mechanism is identical for visual, auditory or tactile stimuli owing to similarity of functioning of topically organised cortico-basal ganglia-thalamocortical loops. © 2012 Springer-Verlag.